[Screening of cardiac autonomic neuropathy in a group of adolescents and young adult Cameroonians with type 1 diabetes]

AIM

We aimed to describe cardiac autonomic neuropathy in a group of young Cameroonians type 1 diabetic patients.

PATIENTS AND METHODS

We conducted a descriptive cross-sectional study including consenting patients with type 1 diabetes and without any other comorbidity, who were followed-up at the type 1 diabetic children's clinic at the Yaoundé central hospital. Cardiac autonomic neuropathy was diagnosed and stage using the five functional tests described by Ewang et al., and the heart rate variability assessment.

RESULTS

We included 60 with a mean age of 18.6±4.9 years, 38.3% of female and a mean duration of diabetes of 5.9±5.1 years. Cardiac autonomic neuropathy was present in 96.7% of participants. Early, confirmed and severe cardiac autonomic neuropathy were found respectively in 8.3%, 86.7% and 1.7% of the patients. The most frequent clinical signs were exercise intolerance, alternating constipation and diarrhea and resting tachycardia.

CONCLUSION

Cardiac autonomic neuropathy is common in young patients with type 1 diabetes. It is important to integrate the assessment of cardiac autonomic reflexes in type 1 diabetic patients' follow-up.

Visual outcome of surgically managed pituitary adenomas followed-up at the Yaoundé Central Hospital

INTRODUCTION

Pituitary adenomas are benign brain tumours arising from the adenohypophysis; representing 10-15% of all intra-cranial tumours. Despite improved management, they are still related to high morbidity. Visual impairment is a common presentation and visual field defects representing 37-96%. We aimed at describing the clinical presentation of operated patients and their visual outcome.

METHODS

We conducted a cross-sectional study for 6 months at the Yaoundé Central Hospital's Neurosurgery, Endocrinology and Ophthalmology departments. We included all patients with histopathological confirmation, having pre-operative visual assessment and operated from January 2010 to June 2016.

RESULTS

Twenty-five participants (50 eyes) were enrolled. Three subtypes of pituitary adenomas were identified: Non-functional pituitary adenomas (64%) > Somatotropinomas (20%) > Prolactinomas (16%). All cases were macroadenomas. The median duration of symptoms was 14 months. All participants presented with vision impairment and 80% with headaches. Craniotomy was used in 88% of cases. The temporal hemifield was the most quantitatively affected; 76% of eyes presented with visual acuity (VA) < 6/12 and 24% of eyes a visual acuity ≥6/12. Thirty percent of eyes presented with optic atrophy; cranial nerve III palsy was the most observed. The Mean deviation (MD), an automated visual field index, improved though non-significant and 16% of eyes had a normal visual field printout after surgery. Left eye mean deviation improved significantly (p = 0.04). After surgery, there was a mild improvement of VA with 62% of eyes having a VA< 6/12 and 38% a VA ≥6/12. There was no ophthalmoplaegia after surgery. Long delay before diagnosis significantly jeopardizes pre-operative and post-operative visual acuity (r = 0.5; p = 0.01).

CONCLUSION

Quantitative vision parameters comparison are suggestive of a potential improvement of vision. This conclusion will be better ascertained on a large-scale sample size. Long delay before diagnosis is associated to poor visual outcome.

HIV treatment is associated with a two-fold higher probability of raised triglycerides: Pooled Analyses in 21 023 individuals in sub-Saharan Africa

BACKGROUND

Anti-retroviral therapy (ART) regimes for HIV are associated with raised levels of circulating triglycerides (TG) in western populations. However, there are limited data on the impact of ART on cardiometabolic risk in sub-Saharan African (SSA) populations.

METHODS

Pooled analyses of 14 studies comprising 21 023 individuals, on whom relevant cardiometabolic risk factors (including TG), HIV and ART status were assessed between 2003 and 2014, in SSA. The association between ART and raised TG (>2.3 mmol/L) was analysed using regression models.

FINDINGS

Among 10 615 individuals, ART was associated with a two-fold higher probability of raised TG (RR 2.05, 95% CI 1.51-2.77, I2=45.2%). The associations between ART and raised blood pressure, glucose, HbA1c, and other lipids were inconsistent across studies.

INTERPRETATION

Evidence from this study confirms the association of ART with raised TG in SSA populations. Given the possible causal effect of raised TG on cardiovascular disease (CVD), the evidence highlights the need for prospective studies to clarify the impact of long term ART on CVD outcomes in SSA.

Ketosis-prone atypical diabetes in Cameroonian people with hyperglycaemic crisis: frequency, clinical and metabolic phenotypes

AIM

It is unclear whether ketosis-prone diabetes is a specific type or a subtype of Type 2 diabetes. We aimed to describe the clinical and metabolic features of ketosis-prone diabetes in a sub-Saharan population.

METHODS

We consecutively enrolled and characterized 173 people with non-autoimmune diabetes admitted for hyperglycaemic crisis at the Yaoundé Central Hospital, Cameroon. Blood samples were collected for fasting glucose, HbA_1c , lipid profile and C-peptide assays with insulin resistance and secretion estimation by homeostasis model assessment. People were classified as having Type 2 diabetes (n = 124) or ketosis-prone diabetes (n = 49). Ketosis-prone diabetes was sub-classified as new-onset ketotic phase (n = 34) or non-ketotic phase (n = 15).

RESULTS

Ketosis-prone diabetes was found in 28.3% of the hyperglycaemic crises. Age at diabetes diagnosis was comparable in Type 2 and ketosis-prone diabetes [48 ± 14 vs 47 ± 11 years; P = 0.13] with a similar sex distribution. Overall BMI was 27.7 ± 13.4 kg/m² and was ≥ 25 kg/m² in 55.8% of those taking part, however, 73.5% of those with ketosis-prone diabetes reported weight loss of > 5% at diagnosis. Blood pressure and lipid profile were comparable in both types. Ketosis-prone diabetes in the ketotic phase was characterized by lower insulin secretion and higher serum triglycerides compared with non-ketotic ketosis prone and Type 2 diabetes. Type 2 and ketosis prone diabetes in the non-ketotic phase were comparable in terms of lipid profile, blood pressure, waist-to-hip ratio, BMI and fat mass, insulin secretion and insulin resistance indices.

CONCLUSIONS

Ketosis-prone diabetes is likely to be a subtype of Type 2 diabetes with the potential to develop acute insulinopenic episodes.

Performance of three glomerular filtration rate estimation equations in a population of sub-Saharan Africans with Type 2 diabetes

AIM

We evaluated the performance of the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Cockcroft-Gault (CG) equations against creatinine clearance (CrCl) to estimate glomerular filtration rate (GFR) in 51 patients with Type 2 diabetes.

METHODS

The CrCl value was obtained from the average of two consecutive 24-h urine samples. Results were adjusted for body surface area using the Dubois formula. Serum creatinine was measured using the kinetic Jaffe method and was calibrated to standardized levels. Bland-Altman analysis and kappa statistic were used to examine agreement between measured and estimated GFR.

RESULTS

Estimates of GFR from the CrCl, MDRD, CKD-EPI and CG equations were similar (overall P = 0.298), and MDRD (r = 0.58; 95% CI: 0.36-0.74), CKD-EPI (r = 0.55; 95% CI: 0.33-0.72) and CG (r = 0.61; 95% CI: 0.39-0.75) showed modest correlation with CrCl (all P < 0.001). Bias was -0.3 for MDRD, 1.7 for CKD-EPI and -5.4 for CG. All three equations showed fair-to-moderate agreement with CrCl (kappa: 0.38-0.51). The c-statistic for all three equations ranged between 0.75 and 0.77 with no significant difference (P = 0.639 for c-statistic comparison).

CONCLUSIONS

The MDRD equation seems to have a modest advantage over CKD-EPI and CG in estimating GFR and detecting impaired renal function in sub-Saharan African patients with Type 2 diabetes. The overall relatively modest correlation with CrCl, however, suggests the need for context-specific estimators of GFR or context adaptation of existing estimators.

H3Africa multi-centre study of the prevalence and environmental and genetic determinants of type 2 diabetes in sub-Saharan Africa: study protocol

The burden and aetiology of type 2 diabetes (T2D) and its microvascular complications may be influenced by varying behavioural and lifestyle environments as well as by genetic susceptibility. These aspects of the epidemiology of T2D have not been reliably clarified in sub-Saharan Africa (SSA), highlighting the need for context-specific epidemiological studies with the statistical resolution to inform potential preventative and therapeutic strategies. Therefore, as part of the Human Heredity and Health in Africa (H3Africa) initiative, we designed a multi-site study comprising case collections and population-based surveys at 11 sites in eight countries across SSA. The goal is to recruit up to 6000 T2D participants and 6000 control participants. We will collect questionnaire data, biophysical measurements and biological samples for chronic disease traits, risk factors and genetic data on all study participants. Through integrating epidemiological and genomic techniques, the study provides a framework for assessing the burden, spectrum and environmental and genetic risk factors for T2D and its complications across SSA. With established mechanisms for fieldwork, data and sample collection and management, data-sharing and consent for re-approaching participants, the study will be a resource for future research studies, including longitudinal studies, prospective case ascertainment of incident disease and interventional studies.

Community-based peer support significantly improves metabolic control in people with Type 2 diabetes in Yaoundé, Cameroon

AIMS

To examine the effectiveness of a community-based multilevel peer support intervention in addition to usual diabetes care on improving glycaemic levels, blood pressure and lipids in patients with Type 2 diabetes in Yaoundé, Cameroon.

METHODS

A total of 96 subjects with poorly controlled Type 2 diabetes (intervention group) and 96 age- and sex-matched controls were recruited and followed up over 6 months. The intervention subjects underwent a peer support intervention through peer-led group meetings, personal encounters and telephone calls. Both intervention subjects and controls continued their usual clinical care. HbA1c , blood pressure, blood lipids and self-care behaviours were measured at 0 and 6 months.

RESULTS

There was significant reduction in HbA1c in the intervention group [-33 mmol/mol (-3.0%)] compared with controls [-14 mmol/mol (-1.3%)]; P < 0.001. Peer support also led to significant reductions in fasting blood sugar (-0.83 g/l P < 0.001), cholesterol (-0.54 g/l P < 0.001), HDL (-0.09 g/l, P < 0.001), BMI (-2.71 kg/m² P < 0.001) and diastolic pressure (-6.77 mmHg, P < 0.001) over the 6-month period. Also, diabetes self-care behaviours in the intervention group improved significantly over the 6 months of peer support.

CONCLUSION

Community-based peer support, in addition to usual care, significantly improved metabolic control in patients with uncontrolled Type 2 diabetes in Yaoundé, Cameroon. This could provide a model for optimizing diabetes care and control in other settings with limited healthcare and financial resources.

Genetic association studies of obesity in Africa: a systematic review

Obesity is increasing in Africa, but the underlying genetic background largely remains unknown. We assessed existing evidence on genetic determinants of obesity among populations within Africa. MEDLINE and EMBASE were searched and the bibliographies of retrieved articles were examined. Included studies had to report on the association of a genetic marker with obesity indices and the presence/occurrence of obesity/obesity trait. Data were extracted on study design and characteristics, genetic determinants and effect estimates of associations with obesity indices. According to this data, over 300 polymorphisms in 42 genes have been studied in various population groups within Africa mostly through the candidate gene approach. Polymorphisms in genes such as ACE, ADIPOQ, ADRB2, AGRP, AR, CAPN10, CD36, C7orf31, DRD4, FTO, MC3R, MC4R, SGIP1 and LEP were found to be associated with various measures of obesity. Of the 36 polymorphisms previously validated by genome-wide association studies (GWAS) elsewhere, only FTO and MC4R polymorphisms showed significant associations with obesity in black South Africans, Nigerians and Ghanaians. However, these data are insufficient to establish the true nature of genetic susceptibility to obesity in populations within Africa. There has been recent progress in describing the genetic architecture of obesity among populations within Africa. This effort needs to be sustained via GWAS studies.

Trends and future projections of the prevalence of adult obesity in Saudi Arabia, 1992-2022

The prevalence of obesity among adults in Saudi Arabia increased from 22% in 1990-1993 to 36% in 2005, and future projections of the prevalence of adult obesity are needed by health policy-makers. In a secondary analysis of published data, a number of assumptions were applied to estimate the trends and projections in the age-and sex-specific prevalence of adult obesity in Saudi Arabia over the period 1992-2022. Five studies conducted between 1989 and 2005 were eligible for inclusion, using body mass index (BMI) ≥ 30 kg/m(2) to define obesity. The overall prevalence of obesity was projected to increase from around 12% in 1992 to 41% by 2022 in men, and from 21% to 78% in women. Women had much higher projected prevalence than men, particularly in the age groups 35-44, 45-54 and 55-64 years. Effective national strategies are needed to reduce or halt the projected rise in obesity prevalence.

Prevalence of anxiety and depression among diabetic African patients in Guinea: association with HbA1c levels

AIM

The prevalence and risk factors associated with symptoms of anxiety and depression were determined in African people with diabetes.

METHODS

This cross-sectional study involved 491 outpatients with type 2 diabetes (T2D) recruited from four diabetes clinics (Conakry, Labé, Boké and Kankan) in Guinea. The Hospital Anxiety and Depression Scale (HADS) was used to evaluate symptoms of anxiety and depression. Logistic regression analysis stratified by gender was performed to identify the associated risk factors.

RESULTS

Anxiety and depression symptoms were present in 58.7% and 34.4%, respectively, of the 491 patients with T2D (62.7% women, mean±SD age: 57.9±10.2years). Odds ratios (95% CI) of risk factors independently associated with anxiety were urban residence [2.98 (1.81-4.89)] in women, and low socioeconomic status [0.19 (0.05-0.70)] and HbA1c≥9.0% [2.61 (1.0-6.39)] in men. Factors associated with depression were urban residence [2.13 (1.27-3.58)], older age [1.03 (1.01-1.06)], low socioeconomic status [2.21 (1.34-3.66)] and no previous measurement of HbA1c [12.45 (1.54-100.34)] in women, and insulin therapy [2.28 (1.05-4.92)] and HbA1c≥9.0% [3.85 (1.02-14.48)] in men.

CONCLUSION

Anxiety and depression symptoms in people with type T2D are common in Guinea. Urban residence, low socioeconomic status and high levels of HbA1c were significantly associated with a greater risk of anxiety and depression, highlighting the psychological burden related to diabetes in Africa.

Influence of migration on characteristics of type 2 diabetes in sub-Saharan Africans

AIM

This study compared the clinical and biochemical characteristics and microvascular complications found in three groups of type 2 diabetes (T2D) patients: Africans living in Africa; African immigrants living in France; and Caucasians living in France.

METHODS

Diagnosed T2D Africans living in Cameroon (n=100) were compared with 98 African migrants diagnosed with T2D after having moved to France, and a group of 199 T2D Caucasian patients living in France. All underwent clinical and biochemical evaluations, and all were assessed for microvascular complications.

RESULTS

The median duration of stay of the migrants in France was 15years before being diagnosed with diabetes. Despite similar durations of diagnosis, they were 8.9years younger at the time of diagnosis than Africans living in Cameroon (P<0.001). Caucasians and African immigrants in France had lower HbA1c values than Africans in Cameroon (P<0.001); they were also more aggressively treated for hypertension and dyslipidaemia and, therefore, had significantly lower blood pressure levels and better lipid profiles. Diabetic nephropathy and retinopathy rates were higher in Cameroon than in the two other groups. After adjusting for age, diabetes duration, HbA1c, hypertension and other covariates, only the prevalence of diabetic nephropathy (OR: 5.61, 95% CI: 2.32-13.53; P<0.0001) was higher in Cameroon compared with those living in France.

CONCLUSION

Our results suggest that Africans who emigrate to France may develop diabetes earlier than those staying in their home country. However, the latter may be a reflection of late diagnosis of diabetes. Also, the less adequate diabetes and hypertension control in the latter would explain their higher rates of nephropathy. Large-scale cohorts are now warranted to substantiate these observations.

Validation of an enzyme-linked immunosorbent assay for C-peptide analysis in Cameroon

AIMS

To validate an ELISA method for C-peptide analysis in Cameroon.

METHODS

We evaluated the linearity, detection limit, functional sensitivity, precision and accuracy, and further investigated for cross-reactivity by proinsulin, and interferences by lipids, bilirubin and hemoglobin. This method was compared with the Roche electrochemiluminescence immunoassay. C-peptide stability was assessed following a series of freeze-thaw cycles, and after storage at room temperature. The C-peptide reference range was determined by analyzing fifty plasma samples of Cameroonians without diabetes.

RESULTS

The ELISA was linear at least up to 7.09 μg/L, and had a detection limit of 0.09 μg/L, and a functional sensitivity of 0.32 μg/L. The inter- and intraassay %CV were 2.9-9.9%, and 5.2-9.4%, respectively. Recoveries were 81-94% in serum, and 93-98% in buffer. Comparison with the ECLIA yielded a good correlation coefficient (R(2)=0.98). There was no cross-reactivity with proinsulin, and no interference with lipids, bilirubin and hemoglobin. C-peptide was stable at room temperature for 24 h and up to 7 freeze-thaw cycles for medium (1-6 μg/L) and high (>6 μg/L) levels (<-15°C and <-70°C). The reference range for C-peptide was 0.38-3.63 μg/L.

CONCLUSIONS

This method is suitable for C-peptide analysis in low-income countries like Cameroon.

Fasting blood glucose and insulin sensitivity are unaffected by HAART duration in Cameroonians receiving first-line antiretroviral treatment

AIMS

This study assessed the relationship between highly active antiretroviral therapy (HAART) duration and cardiometabolic disorders in HIV-infected Cameroonians.

METHODS

HIV-infected Cameroonians aged 21 years or above were cross-sectionally recruited at the Yaoundé Central Hospital, a certified HIV care centre, and their anthropometry, body composition (impedancemetry), fasting blood glucose (FBG) and lipid levels, and insulin sensitivity (IS; short insulin tolerance test) were measured.

RESULTS

A total of 143 participants with various durations of HAART [treatment-naïve (n=28), 1-13 months (n=44), 14-33 months (n=35) and 34-86 months (n=36)] were recruited. They were mostly women (72%), and had a mean age of 39.5 (SD: 9.8) years. Half (52%) were using a stavudine-containing regimen. There was a significant trend towards a positive change in body mass index and waist-to-hip ratio with increasing duration of HAART (all P=0.02). Systolic (P=0.04) and diastolic (P=0.03) blood pressure, total cholesterol (P=0.01), prevalence of hypertension (P=0.04) and hypercholesterolaemia (P=0.007) were also significantly increased with HAART duration, whereas triglycerides, FBG and IS were unaffected. Clustering of metabolic disorders increased (P=0.02 for ≥1 component of the metabolic syndrome and P=0.09 for ≥2 components) with HAART duration.

CONCLUSION

HAART duration is associated with obesity, fat distribution, blood pressure and cholesterol levels in HIV-infected Cameroonians, but does not appear to significantly affect glucose metabolism.

Would sickle cell trait influence the metabolic control in sub-Saharan individuals with type 2 diabetes?

AIMS

To determine the prevalence and effects of sickle cell trait on metabolic control in a Cameroonian diabetic population in a tertiary care setup.

METHODS

This was a cross-sectional study involving 73 consecutive outpatients with Type 2 diabetes recruited from the Yaounde National Diabetes and Obesity Centre. Sickle cell trait status was based on haemoglobin electrophoresis. Metabolic control was assessed by plasma glucose and HbA(1c), and comparisons made between participants with and without sickle cell trait, with adjustment for confounders through linear regressions models.

RESULTS

The prevalence of sickle cell trait was 19%, without sex difference, and comparable with figures in individuals without diabetes in this setting. Participants with diabetes and sickle cell trait were older than the non-trait participants (66 vs. 58 years, P = 0.02). Otherwise, clinical and biological profile including indicators of metabolic control were similarly distributed between trait and non-trait participants (all P >0.08). After adjustment for confounders, sickle cell trait was unrelated to fasting glucose (β = 0.02; 95% confidence interval -37.68-43.30) and HbA(1c) (β = -0.03, 95% confidence interval -1.18-0.93), and did not affect the relationship between the two markers of diabetes control (β = -0.03, 95% confidence interval -1.18-0.89).

CONCLUSIONS

Sickle cell trait was as frequent in this subgroup of patients with Type 2 diabetes as in the general population, suggesting no specific association with diabetes. It does not affect the metabolic control of diabetes. However, how this translates into long-term outcome needs to be fully elucidated in this setting, with an increasing population with both sickle cell trait and diabetes mellitus.

Potential of Spirulina Platensis as a Nutritional Supplement in Malnourished HIV-Infected Adults in Sub-Saharan Africa: A Randomised, Single-Blind Study

BACKGROUND

Malnutrition is a major global public health issue and its impact on communities and individuals is more dramatic in Sub-Saharan Africa, where it is compounded by widespread poverty and generalized high prevalence of human immunodeficiency virus (HIV). Therefore, malnutrition should be addressed through a multisectorial approach, and malnourished individuals should have access to nutritional rehabilitation molecules that are affordable, accessible, rich in nutrient and efficient. We thus assessed the efficacy of two affordable and accessible nutritional supplements, spirulina platensis versus soya beans among malnourished HIV-infected adults.

METHODS

Undernourished patients, naïve of, but eligible to antiretroviral treatment (ART), aged 18 to 35 years were enrolled and randomly assigned to two groups. The first group received spirulina (Group A) as food supplement and the second received soya beans (Group B). Patients were initiated ART simultaneously with supplements. Food supplements were auto-administered daily, the quantity being calculated according to weight to provide 1.5 g/kg body weight of proteins with 25% from supplements (spirulina and soya beans). Patients were monitored at baseline and followed-up during twelve weeks for anthropometric parameters, body composition, haemoglobin and serum albumin, CD4 count and viral load.

RESULTS

Fifty-two patients were enrolled (Group A: 26 and Group B: 26). The mean age was 26.4 ± 4.9 years (Group A) and 28.7 ± 4.8 (Group B) with no significant difference between groups (P = 0.10). After 12 weeks, weight and BMI significantly improved in both groups (P < 0.001 within each group). The mean gain in weight and BMI in Group A and B were 4.8 vs. 6.5 kg, (P = 0.68) and 1.3 vs. 1.90 Kg/m(2), (P = 0.82) respectively. In terms of body composition, fat free mass (FFM) did not significantly increase within each group (40.5 vs. 42.2 Kg, P = 0.56 for Group A; 39.2 vs. 39.0 Kg, P = 0.22 for Group B). But when compared between the two groups at the end of the trial, FFM was significantly higher in the spirulina group (42.2 vs. 39.0 Kg, P = 0.01). The haemoglobin level rose significantly within groups (P < 0.001 for each group) with no difference between groups (P = 0.77). Serum albumin level did not increase significantly within groups (P < 0.90 vs. P < 0.82) with no difference between groups (P = 0.39). The increase in CD4 cell count within groups was significant (P < 0.01 in both groups), with a significantly higher CD4 count in the spirulina group compared to subjects on soya beans at the end of the study (P = 0.02). Within each group, HIV viral load significantly reduced at the end of the study (P < 0.001 and P = 0.04 for spirulina and soya beans groups respectively). Between the groups, the viral load was similar at baseline but significantly reduced in the spirulina group at the end of the study (P = 0.02).

CONCLUSION

We therefore conclude in this preliminary study, firstly, that both spirulina and soja improve on nutritional status of malnourished HIV-infected patients but in terms of quality of nutritional improvement, subjects on spirulina were better off than subjects on soya beans. Secondly, nutritional rehabilitation improves on immune status with a consequent drop in viral load but further investigations on the antiviral effects of this alga and its clinical implications are strongly needed.

Continuous interstitial glucose monitoring in non-diabetic subjects with end-stage renal disease undergoing maintenance haemodialysis

Haemodialysis improves uraemia-induced insulin sensitivity and is therefore likely to induce significant changes in circulating glucose concentrations in end-stage renal disease (ESRD). We aimed to assess clinically relevant circulating glucose changes in patients undergoing chronic maintenance haemodialysis using continuous interstitial monitoring. We investigated 14 non-diabetic ESRD subjects aged 40.6+/-2.4 years. Participants were examined 24-h day pre-dialysis, during the index dialysis session and 24-h post-dialysis with simultaneous measurement of capillary blood glucose and continuous interstitial glucose (CGMS). Participants performed five capillary blood glucose measurements the day before dialysis, and 10 during and after dialysis. Mean capillary blood glucose was 128+/-20mg/dl the day before, 93+/-8mg/dl during haemodialysis, and 105+/-13mg/dl after haemodialysis. There was a significant trend towards lower blood glucose during the session from 105+/-16mg/dl to a 3rd hour nadir of 83+/-15mg/dl (Anova F=2.89, p=0.029). No hypoglycaemia was recorded. Interstitial glucose profile was comparable to capillary glucose profile. Glucose concentrations varied significantly from 126+/-13mg/dl before to 112+/-12mg/dl after haemodialysis respectively (p=0.006). This study provides evidence for the use of CGMS in ESRD and haemodialysis, and demonstrates significant changes in glucose concentrations during and after haemodialysis that would guide treatment monitoring and adjustments.

Waist circumference and obesity-related abnormalities in French and Cameroonian adults: the role of urbanization and ethnicity

OBJECTIVES

To evaluate the effect of urbanization and ethnicity on correlations between waist circumference (WC) and obesity-related cardiovascular risk factors.

METHODS

1471 rural and urban Cameroonians, and 4185 French, from community-based studies, aged > or =25 years, not treated for hypertension, diabetes and dyslipidemia participated in this study. Slopes of obesity-related abnormalities with WC were compared using an interaction term between place of residence and WC.

RESULTS

Women in urban Cameroon and men in France had significantly higher WC and BMI relative to their gender counterparts. Urban Cameroonians had higher abdominal adiposity, but lower BP and better metabolic profile than the French. WC was positively associated to all the obesity-related abnormalities in the three sites except to FPG (both genders) and blood lipids (women) in rural Cameroon. A 5 cm larger WC was associated with a higher increment among urban than rural Cameroonians for diastolic blood pressure (DBP) (women, 1.95/0.63 mm Hg; men, 2.56/1.44 mm Hg), HOMA-IR (women, 0.11/0.05), fasting plasma glucose (FPG) (men, 0.09/-0.01 mmol/l) and triglycerides (women, 0.06/0.01 mmol/l; men, 0.09/0.03 mmol/l), all P<0.05. A 5 cm larger WC was associated with a higher increment among urban Cameroon than French people for DBP (women, 1.95/1.28 mm Hg, P<0.01; men, 2.56/1.49 mm Hg, P<0.01), but with a lower increment for HOMA-IR (women, 0.11/0.14, P<0.05), FPG (women, 0.05/0.09 mmol/l), total cholesterol (women, 0.07/0.11 mmol/l; men, 0.10/0.13 mmol/l) and triglycerides (women, 0.06/0.11 mmol/l; men, 0.09/0.13 mmol/l) all P<0.05.

CONCLUSION

Ethnicity and urbanization modify the association of WC with obesity-related metabolic abnormalities. WC cutoff points derived from Caucasians may not be appropriate for black Sub-Saharan Africans.

An unusual somatotropin and thyreotropin secreting pituitary adenoma efficiently controlled by Octreotide and Pegvisomant

We describe the first case of a 36 year-old male patient with a somatotropin and thyreotropin secreting pituitary adenoma, co-treated by a long-acting releasing somatostatin analog (Octreotide) and a GH receptor antagonist (Pegvisomant). The patient normalized his biological disease activity reflected by hormone levels but his tumor size remained unchanged as measured by MRI. The co-treatment was well tolerated and induced a synergic effect on IGF1 levels that allowed us to use low doses of both therapies.

Hyperglycaemia acutely decreases circulating dehydroepiandrosterone levels in healthy men

OBJECTIVE

This study was conducted in order to evaluate the effect of glucose-insulin homeostasis on adrenal steroids and was designed to separate the effects of hyperglycaemia from those of insulin.

DESIGN

Eight healthy men aged 22.6 +/- 3.4 (SD) underwent an 80 mU/m2/min hyperinsulinaemic euglycaemic 100-min clamp, a 200-min graded glucose infusion at 2-16 mg/kg/min and a measurement of fat mass.

MEASUREMENTS

Circulating glucose, insulin and adrenal steroid levels including dehydroepiandrosterone (DHEA) were determined before and during both infusion tests. Steroid variations in relation to insulinaemia and glycaemia were analysed using univariate, multivariate tests and nonlinear mixed models.

RESULTS

Hyperinsulinaemia induced no significant modification of adrenal steroid levels. By contrast, hyperglycaemia decreased all adrenal steroids except DHEA-sulphate by 47-66%. The drop occurred early, averaging 51% for 17OH pregnenolone and 57% for DHEA at the 80th minute of glucose infusion, whereas blood glucose was 7.1 +/- 1.2 mmol/1. This effect was independent of insulinaemia, fat mass and waist circumference. Thus, we estimated models that could best predict steroid variations according to blood glucose. At thresholds defining impaired fasting glycaemia and diabetes, the estimated decrease in DHEA was 40% and 45%, respectively, culminating at 60% at 9.3 mmol/1 glycaemia, with no detectable further decrease.

CONCLUSIONS

Our data suggest that hyperglycaemia dramatically decreases adrenal androgen levels in men, possibly by acting at early steps of synthesis, independently of insulinaemia and fat mass.

Is capillary ketone determination useful in clinical practice? In which circumstances?

A new method is now available to measure capillary levels of 3-hydroxybutyrate (3HB), one of the three ketone bodies. It is a quantitative and enzymatic test that uses the same equipment as for home capillary blood glucose determination but with specific strips. In comparison to urine ketone test, there is no false negative or false positive results, it is highly correlate to standard automate assays and patients find it more acceptable. Clinical implementations of this new test begin to be reported. Some studies showed an advantage of ketonemia versus ketonuria measurement to detect and to treat diabetic ketoacidosis in the emergency room. In diabetic patients treated with continuous subcutaneous insulin infusion, ketonemia seems to be more relevant to detect lack of insulin. In the current care of patient with type 1 diabetes and especially in children blood ketone test is more effective than urine ketone test to prevent hospitalisation during sick days. For other situations such as diabetic pregnancy or type 2 diabetes, more data are needed to determine if capillary measurement of 3HB is really useful. This new test is easier and less unpleasant than doing urinary test but it is still far more expensive. Further clinical studies are needed to define whether self 3HB monitoring should substitute urinary test in outpatient care.

Biological actions of the incretins GIP and GLP-1 and therapeutic perspectives in patients with type 2 diabetes

Incretin hormones are defined as intestinal hormones released in response to nutrient ingestion, which potentiate the glucose-induced insulin response. In humans, the incretin effect is mainly caused by two peptide hormones, glucose-dependent insulin releasing polypeptide GIP, and glucagon-like peptide-1 GLP-1. GIP is secreted by K cells from the upper small intestine while GLP-1 is mainly produced in the enteroendocrine L cells located in the distal intestine. Their effect is mediated through their binding with specific receptors, though part of their biological action may also involve neural modulation. GIP and GLP-1 are both rapidly degraded into inactive metabolites by the enzyme dipeptidyl-peptidase-IV (DPP-IV). In addition to its effects on insulin secretion, GLP-1 exerts other significant actions, including stimulation of insulin biosynthesis, inhibition of glucagon secretion, inhibition of gastric emptying and acid secretion, reduction of food intake, and trophic effects on the pancreas. As the insulinotropic action of GLP-1 is preserved in type 2 diabetic patients, this peptide was a candidate as a therapeutic agent for this disease. A number of pharmacological strategies have been developed to provide continuous delivery of GLP-1 and to prevent degradation of GLP-1, including continuous administration of GLP-1, DPP-IV inhibitors and DPP-IV resistant GLP-1 analogues. Recent results of the most clinically advanced incretin mimetics confirmed their efficacy to improve glycemic control in type 2 diabetic patients. Further results are expected to confirm the efficacy/safety profile of these compounds, and to find their place in the therapeutic strategy of type 2 diabetes.

Absence of exercise-induced variations in adiponectin levels despite decreased abdominal adiposity and improved insulin sensitivity in type 2 diabetic men

OBJECTIVE

We investigated the effect of an intensive training program on fasting leptin and adiponectin levels.

METHODS

Sixteen middle-aged men with type 2 diabetes were randomly assigned to either a training or control group. The training program consisted of 8 weeks of supervised endurance exercise (75% VO(2peak), 45 min) twice a week, with intermittent exercise (five 2 min exercises at 85% VO(2peak) separated by 3 min exercises at 50% VO(2peak)) once a week, on an ergocycle.

RESULTS

Training decreased abdominal fat by 44%, increased mid-thigh muscle cross-sectional area by 24%, and improved insulin sensitivity by 58% without significant change in body weight. Compared with controls, no significant variation in leptin or adiponectin levels was observed. However, in the trained group, change in adiponectin correlated with change in body weight (Spearman rank correlation, r(s):-0.76, P=0.03) but not with insulin sensitivity or abdominal adiposity variations.

CONCLUSIONS

An 8 week intensive training program inducing a marked reduction in abdominal fat and increase in insulin sensitivity does not affect adiponectin and leptin levels in men with type 2 diabetes.

Adrenal insufficiency and diabetes mellitus secondary to the use of topical corticosteroids for cosmetic purpose

We report a case of symptomatic topical corticosteroid-induced adrenal insufficiency and diabetes in a 46-yr old HIV 1 positive woman of African descent. Topical Betamethasone dipropionate 0.05%-containing creams were used for the purpose of bleaching over a 2 month period prior to the acute episode. She recovered from her acute onset diabetes with ketosis and adrenal insufficiency a few months after withdrawal of corticosteroids. Despite possible discussion about pathophysiology of diabetes because acute-onset remitting diabetes is not rare in patients of African descent, and diabetes may occur in patients taking anti-retroviral treatments, no other cause of a hypothalamo-pituitary-adrenal axis disorder was found. This case suggests that chronic use of high dose topical corticosteroid containing creams should be ruled out in patients presenting with Hypothalamo-Pituitary-Adrenal hypofunction.

Marital status and family size of type 1 diabetic patients in a French cohort

OBJECTIVE

To compare the marital status, the number of offspring and the cumulative incidence of type 1 diabetes in offspring of type 1 diabetic men and women.

METHODS

From the database of patients attending our department, we reviewed the files of all the 352 subjects aged >=40 years with type 1 diabetes and compared male and female patients for whom age, age at diagnosis of diabetes, marital status, socio-economic status, number and age of offspring, diagnosed type 1 diabetes in the offspring could be obtained from patient's record and/or direct interview (86 males and 78 females).

RESULTS

In this population, 73% of women and 81% of men were married or living a marital life (NS), and 35% of women versus 8% of men had no offspring (P<0.0001). The proportion of parents with 2 offspring or more was 43% in females and 61% in males (p=0.03) and was not related to the socio-economic status. The number of offspring with diagnosed type 1 diabetes was small (8/229) and did not show significant association with gender of the parent, with a cumulative incidence of 3.2 and 3.7% in offspring of type 1 diabetic mothers and fathers respectively.

CONCLUSION

Type 1 diabetic women born before 1960 had fewer children than men. In this cohort, there was no difference in the cumulative incidence of type 1 diabetes in offspring of type 1 diabetic men and women despite reduced family size in women.

Metabolic and hormonal effects of five common African diets eaten as mixed meals: the Cameroon Study

OBJECTIVE

To evaluate glycaemic and insulinaemic index and in vitro digestibility of the five most common Cameroonian mixed meals consisting of rice+tomato soup (diet A), bean stew+plantains (B), foofoo corn+ndolé (C), yams+groundnut soup (D), and koki beans+cassava (E).

SUBJECTS

Ten healthy non-obese volunteers, aged 19-31 y, with no family history of diabetes or hypertension.

INTERVENTIONS

A 75 g oral glucose tolerance test followed by the eating of the test diets with carbohydrate content standardized to 75 g every 4 days with blood samples taken at 0, 15, 30, 60, 120 and 180 min. In vitro digestion of each diet according to Brand's protocol.

MAIN OUTCOME MEASURES

Plasma glucose, cholesterol, triglyceride, insulin and C-peptide, with calculation of glycaemic and insulinaemic index defined as the area under the glucose and insulin response curve after consumption of a test food divided by the area under the curve after consumption of a control food containing the same amount of carbohydrate, and digestibility index.

RESULTS

Glycaemic index (GI) varied from 34.1 (diet C) to 52.0% (diet E) with no statistical difference between the diets, and insulinaemic index varied significantly from 40.2% (C) to 70.9% (A) (P=0.03). The digestibility index varied from 18.9 (C) to 60.8% (A) (P<0.0001), and did not correlate with glycaemic or insulinaemic indices. However, carbohydrate content correlated with GI (r=0.83; P=0.04), digestibility index (r=-0.70; P<0.01), and insulinaemic index (r=0.91; P<0.01). Plasma C-peptide and plasma lipids showed little difference over 180 min following the ingestion of each meal.

CONCLUSIONS

Glycaemic index of these African mixed meals are relatively low and might not be predicted by in vitro digestibility index.

Metabolic and immunogenetic prediction of long-term insulin remission in African patients with atypical diabetes

AIMS

We aimed to characterize a cohort of 'atypical' diabetic patients of sub-Saharan African origin and to analyse possible determinants of long-term remission.

METHODS

Over 6 years, we studied the clinical and therapeutic profile of 42 consecutive patients undiagnosed or untreated prior to inclusion presenting with cardinal features of diabetes mellitus. We measured insulin secretion and sensitivity at inclusion. Immunogenetic (anti-GAD, anti-ICA and HLA class II) markers of Type 1 diabetes were compared with a 90-non-diabetic unrelated adult African population.

RESULTS

Twenty-one ketonuric patients (age 42 +/- 9 (sd) years; body mass index (BMI) 26 +/- 3 kg/m2) were initially insulin-treated (IT), and 21 non-ketonuric patients (age 38 +/- 8 years; BMI 26 +/- 5 kg/m2) had oral and/or diet therapy (NIT). Insulin could be discontinued in 47.6% (10/21) IT with adequate glycaemic control (HbA1c 6.7 +/- 1.3%), while insulin was secondarily started in 38.1% (8/21) NIT in expectation of better control. The initial basal (odds ratio (OR) 9.1, 95% confidence interval (CI) 1.3-64.4) and stimulated C-peptide (OR 8.17, 95% CI 1.5-44.1) were independently associated with remission. Insulin resistance was present in all the groups, more marked in the insulin-treated NIT. Anti-GAD antibodies and ICA were rare, but 38.1% IT vs. 1.1% controls had Type 1 diabetes HLA susceptibility haplotypes (P < 0.001) without significant difference between the subgroups.

CONCLUSION

Prolonged discontinuation of insulin is frequent in African diabetic patients initially presenting with signs of insulinopenia. In our patients, long-term insulin therapy was not associated with immunogenetic markers of Type 1 diabetes. The initial measure of insulin secretion seemed a good predictor of long-term remission.

Physical activity and its relationship with obesity, hypertension and diabetes in urban and rural Cameroon

OBJECTIVES

To evaluate and compare physical activity patterns of urban and rural dwellers in Cameroon, and study their relationship with obesity, diabetes and hypertension.

METHODS

We studied 2465 subjects aged >or=15 y, recruited on the basis of a random sampling of households, of whom 1183 were urban dwellers from Yaoundé, the capital city of Cameroon and 1282 rural subjects from Bafut, a village of western Cameroon. They all had an interviewer-administered questionnaire for the assessment of their physical activity and anthropometric measurements, blood pressure and fasting blood glucose determination. The procedure was satisfactorily completed in 2325 (94.3%) subjects. Prevalences were age-adjusted and subjects compared according to their region, sex and age group.

RESULTS

Obesity was diagnosed in 17.1 and 3.0% urban and rural women, respectively (P<0.001), and in 5.4 vs 1.2% urban and rural men, respectively (P<0.001). The prevalence of hypertension was significantly higher in urban vs rural dwellers (11.4 vs 6.6% and 17.6 vs 9.1% in women and men, respectively; P<0.001). Diabetes was more prevalent in urban compared to rural women (P<0.05), but not men. Urban subjects were characterized by lower physical activity (P<0.001), light occupation, high prevalence of multiple occupations, and reduced walking and cycling time compared to rural subjects. Univariate analysis showed significant associations between both physical inactivity and obesity and high blood pressure. The relationship of physical inactivity with hypertension and obesity were independent in both urban and rural men, but not in women. Body mass index, blood pressure and glycaemia were higher in the first compared with the fourth quartiles of energy expenditure.

CONCLUSION

Obesity, diabetes and hypertension prevalence is higher in urban compared to rural dwellers in the populations studied. Physical activity is significantly lower and differs in pattern in urban subjects compared to rural. Physical inactivity is associated with these diseases, although not always significant in women.

Diabetes in Africans. Part 2: Ketosis-prone atypical diabetes mellitus

Diabetes is increasing with ageing and changes in lifestyle in populations of African ancestry as described in the first part of this review. Apart from classical type 1 and Type 2 diabetes, atypical presentations are observed in these populations, especially "tropical" and "ketosis-prone" atypical diabetes. Ketosis-prone atypical diabetes that has been classified by ADA as idiopathic Type 1 diabetes or Type 1b is the most common atypical form. It is characterised by an acute initial presentation with severe hyperglycaemia and ketosis, as classical Type 1 diabetes. In the subsequent clinical course after initiation of insulin therapy, prolonged remission is often possible with cessation of insulin therapy and maintenance of appropriate metabolic control. Metabolic studies showed a markedly blunted insulin secretory response to glucose, partially reversible with the improvement of blood glucose control. Variable levels of insulin resistance are observed, especially in obese patients. Pancreatic B-cell autoimmunity is an exceptional finding. Association with type 1 susceptibility HLA alleles is variable. The molecular mechanisms underlining the insulin secretory dysfunction are still to be understood and may involve gluco-lipotoxicity processes, glucagon dysregulation, effect of stress, or may be genetically determined. The present review summarises the available clinical and metabolic features and suggests some pathogenetic hypotheses and principles of management for the ketosis-prone atypical diabetes of the Africans.

Development and validation of a questionnaire for the assessment of physical activity in epidemiological studies in Sub-Saharan Africa

OBJECTIVE

To develop and validate a questionnaire for measuring physical activity within Sub-Saharan Africa. Methods We designed the Sub-Saharan Africa Activity Questionnaire (SSAAQ), based upon existing questionnaires and an activity survey carried out in Cameroon. The questionnaire targeted past-year occupation, walking/cycling and leisure-time activities, and was administered by trained interviewers on two occasions, 10-15 days apart to 89 urban and rural consenting Cameroonians aged 19-68 years. Reliability was assessed by inter-interview comparison and repeatability coefficients (standard deviation of the test-retest difference). Validation was performed against a 24-hour heart rate monitoring and accelerometer recording.

RESULTS

The questionnaire was highly reproducible (rho = 0.95; P < 0.001). The inter-interview difference did not differ significantly from 0, with a repeatability coefficient of 0.46-1.46 hours. Total energy expenditure from the questionnaire was significantly correlated to heart rate monitoring (rho = 0.41-0.63; P < 0.05) and accelerometer measures (rho = 0.60-0.74; P < 0.01). Subject's self ranking of their activity did not match the questionnaire's quartiles of activity.

CONCLUSIONS

The present study presents the design and confirms the reliability and validity of SSAAQ in a rural and urban population of Cameroon and shows that subject's self ranking of activity might not accurately serve epidemiological purpose.

Diabetes in Africans. Part 1: epidemiology and clinical specificities

The prevalence of diabetes in African communities is increasing with ageing of the population and lifestyle changes associated with rapid urbanisation and westernisation. Traditional rural communities still have very low prevalence, at most 1-2%, except in some specific high-risk groups, whereas 1-13% or more adults in urban communities have diabetes. Type 2 diabetes is the predominant form (70-90%), the rest being represented by typical type 1 patients and patients with atypical presentations that require more pathophysiological insight. Due to the high urban growth rate, dietary changes, reduction in physical activity, and increasing obesity, it is estimated that the prevalence of diabetes is due to triple within the next 25 years. In addition, long-term complications occur early in the course of diabetes and concern a high proportion of patients, probably higher than in other ethnic groups, and that could be partly explained by uncontrolled hypertension, poor metabolic control and possible ethnic predisposition. The combination of the rising prevalence of diabetes and the high rate of long-term complications in Africans will lead to a drastic increase of the burden of diabetes on health systems of African countries. The design and implementation of appropriate strategy for early diagnosis and treatment, and population-based primary prevention of diabetes in these high-risk populations is therefore a public health priority.

HLA-DRB1, -DQA1, -DQB1 and DPB1 susceptibility alleles in Cameroonian type 1 diabetes patients and controls

It is known that certain combinations of alleles within the human leucocyte antigen (HLA) complex are associated with susceptibility or resistance to type 1 diabetes. Variable associations of DR and DQ with type 1 diabetes are documented in Caucasians but rarely in African populations; however, the role of HLA-DP genes in type 1 diabetes remains uncertain. In order to investigate the HLA class II associations with type 1 diabetes in Cameroonians, we used sequence-specific oligonucleotide probing (SSOP) to identify DRB1, DQA1, DQB1 and DPB1 alleles in 10 unrelated C-peptide negative patients with type 1 diabetes and 90 controls from a homogeneous population of rural Cameroon. We found a significantly higher frequency of the alleles DRB1*03 (chi2 = 17.9; P = 0.001), DRB1*1301 (chi2 = 37.4; P < 0.0001), DQA1*0301 (chi2 = 18.5; P = 0.001) and DQB1*0201 (chi2 = 37.4; P < 0.001) in diabetes patients compared to the control group. The most frequent alleles in the control population were DQA1*01, DQB1*0602 and DRB1*15. The DRB1*04 allele was not significantly associated with type I diabetes in our study population. We observed no significant difference between patients and controls in DPB1 allele frequency. In conclusion, the data in Cameroonian diabetes patients suggest the existence of HLA class II predisposing and specific protective markers, but do not support previous reports of a primary association between HLA-DP polymorphism and development of type I diabetes.

Left ventricular mass and systolic function in African diabetic patients: association with microalbuminuria

OBJECTIVE

To assess echocardiographic evidence of cardiomyopathy and its association with microalbuminuria in type 2 normotensive non-proteinuric diabetic patients.

MATERIAL AND METHODS

Forty consecutive normotensive non-proteinuric type 2 diabetic patients were studied. Body mass index, blood pressure, urinary albumin excretion, ECG at rest and after exercise, left ventricular mass, and shortening fraction using two-dimensional and M-mode echocardiography were measured in every patient.

RESULTS

Among the 40 patients studied, 17 (42.5%) presented with microalbuminuria, 16 (40.0%) with left ventricular hypertrophy, 22 (55.0%) with systolic dysfunction and 3 (7.5%) with ECG changes compatible with cardiac ischaemia. No significant difference existed between normoalbuminuric and microalbuminuric patients for age, known duration of diabetes, body mass index, systolic and diastolic blood pressure. Ventricular mass correlated to urinary albumin excretion rate (r=0.34; p=0.04) and shortening fraction to diastolic blood pressure (r = - 0.40; p=0.01).

CONCLUSION

Left ventricular structure and function might be altered in African type 2 diabetic patients in the absence of hypertension, and microalbuminuria may be an early biochemical marker of these abnormalities.

Reduced insulin secretion in offspring of African type 2 diabetic parents

OBJECTIVE

To determine the early biochemical predictors of increased susceptibility to develop diabetes in offspring of African type 2 diabetic parents.

RESEARCH DESIGN AND METHODS

A total of 69 offspring (case subjects) of 26 families in Cameroon with at least one type 2 diabetic parent were studied, and 62 offspring (control subjects) from 25 families in Cameroon with no parent with type 2 diabetes underwent an oral glucose tolerance test. Early insulin secretion was calculated using the ratio of the 0- to 30-min incremental insulin values to the 0- to 30-min incremental glucose. Anthropometric parameters were also measured.

RESULTS

Of the case subjects, 23% were glucose intolerant (4% with diabetes and 19% with impaired glucose tolerance [IGT]) compared with 6.5% (all with IGT) of control subjects (P = 0.02). There was also an increasing prevalence of glucose intolerance, especially IGT with increasing number of glucose-intolerant parents. Fasting serum insulin levels were not different in the two groups; however, at 30 min, the case subjects had lower insulin levels than the control subjects (P < 0.006). Case subjects with IGT had lower 30-min insulin concentration, early insulin secretion, and 2-h insulin levels than those with normal glucose tolerance (NGT) (F = 4.1, P < 0.05; F = 4.1, P < 0.04; and F = 5.1, P < 0.03, respectively). Furthermore, case subjects with NGT and IGT had lower early insulin secretion than control subjects (F = 4. 1, P < 0.03). These differences remained after adjustment for BMI and regardless of the status of parental diabetes. Two-hour insulin concentration showed a positive association (odds ratio = 0.95 CI 0.90-0.99, P = 0.039) with IGT in the case subjects.

CONCLUSIONS

Diabetes and IGT are more prevalent in the offspring of African type 2 diabetic parents, and this may be due to an underlying degree of beta-cell impairment marked by reduced early-phase insulin secretion.